The invention pertains to an apparatus for horizontally pushing articles, particularly hollow glass articles, from a stationary depositing plate of an IS glass molding machine onto a belt conveyor that moves rectilinearly with a uniform speed.
The process of manufacturing hollow glass articles from the molding of a glass gob in a blank mold and the finish mold up to the treatment in a cooling furnace is characterized by numerous transport and manipulation processes, wherein the attainable production yield depends on the speed and reliability of these processes. This applies, among other things, to the process of transferring articles that were removed from a finish mold and deposited on a stationary depositing plate onto a moving belt conveyor, on which the articles need to be positioned successively in the form of a row arrangement. Since such a belt conveyor in IS-machines (individual section) usually cooperates with a plurality of manufacturing stations, each of which is provided with a depositing plate, on which at least two finish-molded articles need to be deposited in a cyclic fashion, the transfer onto the belt conveyor needs to be coordinated with the speed thereof, as well as the operating cycle of the manufacturing stations, in order to form a defined row on the belt.
Various types of transfer pushers are known as manipulation elements that directly cooperate with the hollow glass articles, wherein the ends of the transfer pushers that face the article feature pushing fingers that are in contact with the articles during the transfer process. The transfer process needs to be realized in such a way that it can be carried out quickly within a predetermined time interval. It is also necessary to prevent the article standing on the depositing plate from a toppling over and being damaged; that is the article needs to stands on the belt conveyor in a defined position, namely a transfer point, at the end of the transfer curve and move with the same speed as the belt. Depending on the transfer curve realized between a receiving point on the depositing plate and a transfer point on the belt conveyor, however, the article is subjected to accelerations in the radial and the tangential direction, wherein these accelerations need to be controlled to achieve an accurately positioned and undamaged transfer onto the belt conveyor. However, the control becomes problematic and requires special safety measures at higher speeds.
EP 1 627 858 A1 discloses a transfer apparatus having a lever that can be pivoted about a vertical, stationarily arranged axis on one of its ends. On its other end it carries one end of a second lever such that it can also be pivoted about a vertical axis, wherein a transfer pusher that is equipped with three pushing fingers is supported on the other end of the second lever such that it can be pivoted about a horizontal axis. The rotations of the first lever about the stationary axis, of the second lever relative to the first lever and of the transfer pusher relative to the second lever are realized with drives that can be controlled independently of one another such that a transfer curve from a receiving point on a depositing plate up to a transfer point can be realized in the form of a superposition of three partial movements. At least two of the rotary drives required for realizing these three partial movements are arranged stationarily.
DE 10 2004 010 238 B3 discloses another transfer apparatus, in which the transfer movement of a transfer pusher carrying pushing fingers between a depositing plate and a moving belt conveyor is realized in the form of three rotational movements that can be controlled independently of one another. The superposition of the three movements results in a transfer curve that extends from a receiving point on the depositing plate to a contact point tangentially to the moving direction of the belt conveyor and continues with the same speed and direction as the movement of the belt conveyor by a defined linear path element after this contact point until a separation point is reached, at which the pushing fingers are disengaged. This measure serves for additionally securing the position of the hollow glass articles during the transfer. However, these transfer apparatuses, having three axes to be controlled, are comparatively complex with respect to the control technology, and, in particular their manufacturing design because three stationarily arranged rotary drives are required.
GB 2 435 025 A discloses a comparable apparatus, in which the transfer curve of a transfer pusher between a depositing plate and a moving belt conveyor is realized in the form of a superposition of the rotational movements generated by two rotary drives that are stationarily arranged adjacent to one another. In this case, two gear mechanisms are required, namely for the rotation about a common main axis and for transmitting a rotational movement from the main axis to the rotational axis of the transfer pusher. This means that both gear mechanisms always rotate during a rotation of the transfer pusher.
CH 698 252 B1 discloses another apparatus, in which the transfer curve of a transfer pusher between a depositing plate and a moving belt conveyor is realized in the form of a superposition of the rotational movements generated by two rotary drives that are stationarily arranged in series. In this case, one gear mechanism is required, wherein one of the two rotary drives consists of a hollow shaft motor and the rotational movement also needs to be transmitted to the rotational axis of the transfer pusher. The difficulty in this respect would consist of locating a suitable hollow shaft motor.
Due to a reduction of the number of rotary drives to be used and controlled, the apparatuses disclosed in documents GB 2 435 025 A and CH 698 252 Bi provide certain advantages in comparison with the initially cited state of the art that is characterized by three rotary drives. However, these solutions also have the disadvantage that the two stationarily arranged rotary drives require the use of comparatively complicated gear mechanisms to constructively realize the superposition of two rotational movements. The gear mechanism components that are inevitably moved during each actuation of the transfer pusher increase the inertia of the entire system. In addition, elements are used in the surroundings of a glass molding machine, i.e., in an atmosphere that is characterized by heat, oil, dust and glass fragments and reduces the service life of the gear mechanism components. This is associated with high maintenance expenditures.
Document DE 10 2004 007 507 A1 discloses a device for shifting glass articles that is designed for transferring these glass articles from a first belt, on which they are successively arranged in a row, namely a relatively fast moving transverse belt, onto a second belt that moves relatively slow and perpendicular to the first belt, namely a longitudinal belt, on which they are adjacently arranged in groups transverse to the transport direction. The glass articles are transferred, for example, into a cooling furnace by means of the longitudinal belt, wherein the width of the longitudinal belt depends, among other things, with the width of the cooling furnace. In contrast to the initially cited state of the art, this consequently does not concern a movement from a depositing plate, i.e., a stationary starting point, onto a moving belt such that the kinematical conditions are different in this respect. This apparatus is characterized by a pusher bar that simultaneously takes hold of a certain number of glass articles that depends on the length of the bar on the first belt and transfers said glass articles onto the second belt while realizing an adaptation to the different speeds of the belts, wherein this transfer movement is realized in the form of a superposition of three rotational movements and consequently three rotary drives, one of which is arranged stationarily.